Radio signaling system



Aug. 21, 1928. 1,681,564

a. M. WRIGHT RADIO S IGNALING SYSTEM Original Filed March 2. 1922 HETERODYNE REeTlF'IEF? I: R 7- A J HETE RODYNE 7} '2 TELEPHONE I? f TELEPHONE FILTERS avwewtoz G ORGE M.WR|GHT the other is the mean of the other of the two transmitted frequencies and the third, and I rectify .the beatfrequencies thus produced I c Application filed March 2, 1922, Serial No.

Patented Au 21, 1 928.

UNITED STATES rona'rron F annnrcan conro'nnrioiv or DELAWARE.

nAnIo srenenme sYs'mEM;

When incoming continuous-waves are combined with locally generated'oscillations the frequency of the beat note is equal. to the difference between the local frequency and that of the signals. 7 Consequently the same heat frequencycan be obtained from a single lo-z cally generated frequency and twoichiferent z vention', what I claim is:" V

transmitted frequencies, one higher and the other lower than the local frequency.

-According to this invention I provide asingle transmitting aerial with means which acting separately cause waves of two different frequencies to be transmitted and acting together cause waves of at third frequency to be transmitted, and I provide at the receiving station means for generating two frequencies one of Wl'ilClllS the mean of one of the two transmitted frequencles and the third while i and pass them to two differently tuned receivers. i

My invention is illustrated by theaccompanying drawing which is a diagram show ing a transmitting station A and a receiving station B. At A, K, and K, are sending keys having their contacts connected to different points in the tuning inductanceL of a plain aerial so that when either or both of the keys are depressed the wave length is shortened."

Suppose that is the wave length when neither key is down, A, that when K, is; down, a, that when K is down and a, that when both 'keys are down, and that the wave length is progressively shortened from to/\ At the receiving station aretwo heterodyne local generators H H andafter rectification at R tl'ie resulting low frequency beat currents pass through two coils C 'C coupled to fiItersF Fg, connected to telephones T ,T ,'orother suitable recording devices and tun'edtO-dif fere-nt frequencies n, and The oscillator H is adjusted to give a frequency equal to the mean of the frequenciesof a, and a, which gives thebeat note a that is to say, signals are heard in the telephone T when the key K is depressed whether the key K is down or not, therefore signaling canbe effected on key K and is unaffected by'the openingan d closing of the key K Similarly the generator H is adjusted to give the mean between the frequencies of A, and a, and thereforesignaling can be effected onkeyK and in unaffected by the position ofkey K It is there- 540,387, and in Great Britain July 29, 1925. 7

March a, 1921. Renewed it forepossible to signal on both keys simultaneously w thout any interference taking place in the two receiving devices. It isclear thatthe two locally generated, frequencies 1. In high frequency signalingisystems, a plurality of means at the sending station adapted to act separately and-jointly tovary Y the sending frequency, each of said means acting separately being adapted to produce a different frequency, and acting jointlyto pro-' duce a third frequency and a pair of beatrecervers each responsive to a different frequeney, one responsive to one of the first mentioned frequencies and to the third frequency andthe otheriresponsive to the other of the first mentioned frequencies and to the third" frequency.

2; A system of prising at thes'ending station means which actingseparately cause waves of two different frequencies to be transmitted and acting to-ti gether cause waves of a third frequencyto be transmitted and at-the receiving station means for generating two'frequencies one of which is the mean of one of the said two transmitted frequencies and the third while the other is the mean of the other ofthe two transmitted frequencies andthe thirdfand two-receivers each of which is tuned to one of the two beat frequencies thus produced.

31 A system of wireless telegraphy com prising at the sending station means which acting separately cause waves of two differcnt frequencies to be transmitted and 'acting together cause waves ofa third frequency to be transmitted and at the receiving station meansfor generating two frequencies one of whichis"theanean ofoneof the said two transmittedfrequenciesand the third, while rt heother isthe mean of the other of the two transmitted frequencies and the third, and'two receivers each of which is tuned to one of the two beat frequencies thus produced,

said two meanfrequeneiesbeing adapted to give a different beat frequency with each wireless telegraphy com- GEORGE MAURIGE'WBIGHT, or CHESTERFIELD, rinerannnssienon T0 timeout signals;

receiving aerial two frequencies one of which is the mean of the frequencies transmitted whenone key is depressed while the other is the mean of the frequencies transmittedwhen the other key is depressed, and separate means for detecting the beatfrequencies 5. The method of radio signaling which consists in transmitting one set of signals on' either of two frequencies alternatively, transmitting another set of signals on either of two frequencies alternatively, one of said frequenproduced for each set of signals, the beating frequency'for each set remaining constant,

irrespective of which frequency is transmit-- ting said set of signals. 7

6. The method of radio signaling which comprisestransmitting one set of signals on two selected frequencies alternatively, transmitting a second set of signals on one of said selected frequencies and a third frequency alternatively, and receiving said signals by combining with the signals of the first set a frequency which 1s the mean of those used in the transmission of such set of si nals and b combining with the signals of the second set a frequency which 1s the mean of those used in the transmission of such second set of 'l In radio receiving apparatus adapted to receive two sets of signals transmitted on three frequencies, of'which one frequencyis common to both sets of signals, thecombination of means for producing a frequency, giving a beat frequency with said common frequency and another of said frequencies, means for producing a second frequency givingja differcy and the third of said frequencies, means for detecting both of said beat frequencies, and a plurality of indicating means, each vbeing arranged to respond to only onedetected beat frequency.

8. In radio receiving apparatus adapted to rece ve two sets of signals transmitted on three-frequencles, of which one frequenc is commonsto both sets ofv signals, the combina-.

tion of means for producing a frequency giving characteristic beat frequencies'with said *common frequency and asecond of said three frequencies, and for producing another frequen'cy giving characteristic beat frequencies with said common frequency and the third of said frequencies said characteristic beat frequencies differing from the previously recited characteristic beat frequencies, and a plurality of indicating means, one of said indi eating means being arranged to respond only to the frequencies produced by the firstof said beat-producing frequencies, and another of i said indicating means lacing-arranged to re spend only to frequencies produced: by the second of said beat-producing frequencies:

'9.- In a wireless telegraph system a transmitting aerial, means associated therewith which acting separately cause waves of two different frequencies to be transmittedand acting together cause waves of a third frequency to be transmitted and a receiving device including I means for generating a frequency which is I a mean of one ofthe two transmitting fre c quencies and, the third whereby an audible beat frequency is produced, and atranslating device associatedwithsaid beat frequency.

10. The method vof receiving oscillating currents whose respective frequencies vary from afirst given frequency to a second given frequency by combining therewith an oscillating current whose frequency .is-a mean of the frequencies of the first mentionedcun rentsivhereby a beat current of substantially constant frequency is produced. j 7

11. The method of receiving high frequency oscillating currents'whose respectivehe s quencies alternate froma first given frequency to a secondgiven frequencyby combining therewith an oscillating currentwhose frequency is a mean of the frequencies of the first mentioned currents and then rectifying and utilizing the combined currentto operate an 7 indicaton c ent beat frequency \Vltll said commonfrequen- 12. A receiving device having input and" "output circuits, means for impressing on the input circuit a signal wave of given frequency,=a heterodyne coupled withthe input circuit, a second heterodyne adjusted for a dif- 'ferent frequency than the first also coupled to said input circuit whereby a compound wave of audible frequency is produced in said output; circuit, a plurality of means coupled to said output circuit each tunedto a' different audible frequency and a translating device assoc'iated'with each of said means; I

' GEORGE MA RICE" WRIGHT. 

